piston materials

[ThatGuy]

Will these parts work for a 1" barrel?
Its a 3/4" PVC cap (a bit bigger than 1" pipe), a screw and nut, and a "rubber packing sheet" I got at Lowes.



Anyone used this rubber before?

Thanks

[Proxywars]

It depends what ur gun is. That rubber will work well. However, use silicone oil and not gun oils or WD40.

[ThatGuy]

silicon oil where the rubber meets the barrel? won't that dry up?

[Proxywars]

Yes. With my old fail pengun the leaked the silicon oil stopped the leaks and sped the piston up increasing velocity and it was consistent for 9 days. BTW my gun broke and leaked because I ran out of silicon oil and put wd40 which wrecked the rubber......

[Packols]

it leaks throu the barrel

[Proxywars]

Yesir. Just stick with silicone and high pressures and you will have no leaks my friend .

[Crna Legija]

Yesir. Just stick with silicone and high pressures and you will have no leaks my friend .

lol silicon wont seal shit make sure you get the barrel square in the barrel and put epoxy around the bolt to stop air going thought there.

Also when you sand the cap to fit in the pipe, do it slowly and keep testing to see as soon as it fit stop the tighter the better so long it slides nicely.

[Gun Freak]

Proxywars... Shut up.

OP, you'll need a washer to hold down the rubber in the front, it will probably just slip off the nut. What chamber size is this for?

[ThatGuy]

2" chamber and 1" barrel

the piston will fit into a 1 1/4" pipe

Should I use this rubber or find something better? if so where would I find it?

[Goats spudz]

i would suggest using material off of a nitrile rubber glove glued onto that thick rubber.

[Proxywars]

Proxywars... Shut up.

OP, you'll need a washer to hold down the rubber in the front, it will probably just slip off the nut. What chamber size is this for?

Geese..... I got myself thinking on my gun how the piston was a tight fit. But with his it's not the same case so he doesn't need oils... My mistake...

lol silicon wont seal crap make sure you get the barrel square in the barrel and put epoxy around the bolt to stop air going thought there.

Also when you sand the cap to fit in the pipe, do it slowly and keep testing to see as soon as it fit stop the tighter the better so long it slides nicely.

Sorry thinking of my gun when I posted that.. Piston got caught on a dent and oil helped it...

[ThatGuy]

I'm not worried about the piston not moving- if It jams I'll use silicon oil or grease but I will try the hard rubber with nitrile rubber gloves

[Proxywars]

You wont need oils unless your piston is a little snug in the chamber. We all would like to see that puppy firing soon though .

[Goats spudz]

You wont need oils unless your piston is a little snug in the chamber. We all would like to see that puppy firing soon though .

Oiling would improve performance as it would allow the piston to move with less friction.

[Technician1002]

I used pipe caps as pistons in 2 of my cannons, The Dragon which used a 2.5 inch cap in a 3 inch pipe and the Mouse Musket which used a 1 inch pipe cap inside a 1.5 inch pipe. Both required sanding to fit. Take your time.

I used rubber o ring seals on the end of the barrel instead of bolting a seal onto the piston.

One thing in common is they eventually crack. Use a bumper to extend the life. Because of this, I no longer use pipe cap pistons except in my ABS test cannon which has an extended bumper.




Showing the cracked pipe cap piston and open breech showing the 1.5 inch inner pipe and o ring seal on the barrel.